JPS63250256A - Call waiting service system - Google Patents

Abstract

PURPOSE:To make it possible to execute a call waiting service even in the midst of communication of data by judged that it is an incoming call while an opposite side is calling to a data terminal when a carrier cutoff is intermittently detected and periodically transmitting a message expressing the effect to the data terminal. CONSTITUTION:If there is an incoming call from a third person in the data terminal 10 while data communication is executed between a center 1 and the data terminal 10, a telephone exchange 8 transmits an incoming call indicating tone to the data terminal 10 every four seconds. Since the speech path is disconnected in the midst of transmitting the incoming call indicating tone, the data transmitted during the transmission of above-mentioned tone becomes an error. Meanwhile, the carrier from the data terminal 10 is not detected during the transmission of the incoming call indicating tone in the MODEM 2 of the center 1 side and a carrier detection signal is obtained in an OFF state. By monitoring the state of the carrier detection signal in a certain period, the incoming call in the midst of communicating to the data terminal 10 can be detected from the change of the carrier detection signal.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a call waiting service system in data communication using a telephone switching network, and in particular, the present invention relates to a call waiting service system in data communication using a telephone switching network, and particularly in data communication between a data terminal and a center or other data terminals. The present invention relates to a call waiting service system in which when a terminal receives a call from a third party, a message to that effect is displayed on the data terminal.

[Conventional technology]

With conventional call waiting services, for example, as described in U.S. Pat. When the call is connected, a call waiting signal is sent to the called party, thereby indicating that the call is connected.

[Problem that the invention seeks to solve]

However, the above-mentioned call waiting service relates to calls during voice calls, and is inappropriate for use in receiving calls from third parties during data communication using a call connection. This is because a data error occurs when the call is disconnected when a call arrives during a communication, and it is impossible for the receiving side to determine whether this error is due to a line error or due to an incoming call during a communication.

SUMMARY OF THE INVENTION An object of the present invention is to provide a call waiting service system that can display a message to the called party when the called party receives a call from a third party during data communication.

[Means for solving problems]

If a data terminal receives a call from a third party while the data terminal is communicating with the other party via a communication communication company in full-duplex mode, the data terminal receives a call from a third party. The telephone line is intermittently disconnected in order for the incoming signal to be sent out, but while the line is disconnected, the carrier from the data terminal is not transmitted to the other party. It is possible to display an incoming call on the terminal.

In other words, if a carrier disconnection is detected intermittently at the other end, the other end determines that the call is a pending call to a data terminal and periodically sends a message to the data terminal indicating this fact. This is achieved by

[For production]

When there is a call waiting signal to a data terminal, a call waiting signal is periodically sent to the data terminal, but while the call waiting signal is being sent, the other party detects a carrier disconnection from the data terminal. will be done. Therefore, when a carrier disconnection is periodically detected, the other party determines that the call is in progress and sends a message to the data terminal indicating this fact. Even while a call waiting signal is being periodically sent to the data terminal, if the other party sends a message periodically, this message can be reliably displayed on the data terminal, and the message will be displayed on the data terminal. This allows the data terminal side to know that a call is in progress.

〔Example〕

The present invention will be explained below with reference to FIGS. 1 to 3.

First, the data communication network according to the present invention will be explained. FIG. 2 shows an example of the network configuration. In this example, as shown in the figure (a data terminal 10 equipped with a telephone 9 performs data communication with the center 1 via a telephone exchange 8 and a relay telephone exchange 7 in a full-duplex manner, In addition to the center 1, general data terminals can also be considered as data communication destinations.If a general data terminal including the data terminal 10 or the center 1 is equipped with a carrier detection function, it is necessary to use a carrier detection function from a third party. An incoming call during data communication can be reliably displayed on the data terminal or center 1 as the destination.

Now, in this example, it is assumed that a call is received during communication to the data terminal 10, and therefore the center 1 is equipped with a carrier detection function in advance.

This function is provided in the modem 2, and while the center 1 exchanges data with the modem 2 via the data transmission/reception vA3, it does not receive the carrier detection signal (CD) from the modem 2 via the carrier detection signal line 4. It is something to be taken. While the carrier detection signal is being obtained, it can be determined that the data terminal 10 is connected to the center 1.

Here, while data communication is being performed between the center 1 and the data terminal 10, an incoming call from a third party is sent to the data terminal 10.
0, the telephone exchange 8 has the data terminal 10.
An incoming call display tone will be sent every 4 seconds. Since the communication path is disconnected while this incoming call indication tone is being sent, data sent during that time will result in an error, but the modem 2 on the center 1 side will detect the carrier from the data terminal 10 while the incoming call indication tone is being sent out. carrier detection signal (CD)
will be obtained as an OFF state. therefore,
The state of the carrier detection signal (CD) is changed at a certain period (for example, 2
00m5), it becomes possible to detect an incoming call to the data terminal 10 from a change in the carrier detection signal (CD).

In this example, as shown in the figure, the state of the carrier detection signal (CD) is read at a fixed period (for example, 200 m5), and
The data are sequentially stored in the shift register 5.

The shift register 5 has a length of N bits (for example, 25), and shifts by 1 bit every time the state of the carrier detection signal (CD) is written from the center 1. Therefore, the shift register 5 has a length of N bits (for example, 25). For example, the state of the carrier detection signal (CD) within 5 seconds is stored. The state of this carrier detection signal (CD) remains ONa'' while there is no incoming call during communication, but turns ON as shown in FIG. 3 when there is an incoming call during communication.

Since the OFF state is repeated, the incoming call to the data terminal 10 can be detected from this state change. Although the OFF state is shown as "1" in FIG. 3, the counter 6 calculates the number of "1" states in the shift register 5 every time the carrier detection signal (CD) is shifted and stored in the shift register 5. The count is displayed. Therefore, the counter 6 indicates the OFF state time of the carrier detection signal (CD) within the last 25 seconds, for example. Carrier detection signal (C
D) OFF state time is approximately 700m5~1,600m
5, so if the value of the counter 6 is within a certain range (3 to 15 in the above example), it can be identified that the incoming call display tone is being sent.

FIG. 1 shows the flow of an example of call waiting service processing according to the present invention at a center. In this case, when communication is started, the processing at center 1 enters a state in which it is monitoring the incoming call display sound, verifies the value of counter 6 at a fixed period (for example, 1 second), and if an incoming call is detected. The state changes to the incoming call display tone "Roh".

This state is provided to determine momentary power outages and line disconnections; if an incoming call is 411'E for 5 seconds, it is determined that a third party has received a call on 61, and a call waiting message is sent. The call waiting message is sent to the terminal IO and the call waiting message is displayed. This state is provided to prevent the call waiting message from colliding with the incoming call display sound and causing an error and not being received by the data terminal 10. While the value of the counter 6 indicates an incoming call, A call waiting message is sent to the data terminal 10 every second.

On the other hand, when a call waiting message is received and displayed on the data terminal 10, the operator switches the line to the telephone 9 and then performs hooking, but when hooking is detected, the telephone exchange 8 disconnects the connection with the third party. It will be a place to do it. Therefore, at the center 1, the carrier from the data terminal 10 is interrupted and the value of the counter 6 becomes thick (but when the value becomes large, the carrier detection signal (CD
) is determined to be rejected and moves to a pending state. While on hold, if the carrier detection signal (CD) continues to be disconnected for 30 seconds, the line will be released, but if the line is reconnected to the data terminal 10 by re-linking on the telephone 9 within 30 seconds, the carrier detection signal (CD) will be released again. CD) is detected, and data communication can be performed again.

As described above, according to the present invention, even during data communication, it is possible to implement a call waiting service by detecting carrier disconnection due to the incoming call display sound and notifying the operator.

〔Effect of the invention〕

As explained above, according to the present invention, there is an effect that call waiting service can be implemented even during data communication.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a flow of an example of call waiting service processing according to the present invention, FIG. 2 is a diagram showing a network configuration of an example of a data communication network according to the present invention, and FIG.
FIG. 3 is a diagram for explaining a method for detecting an incoming call during communication based on carrier disconnection detection. 1... Center, 2... Modem, 5... Shift register, 6... Counter, 7.8... Telephone exchange, 9
...Telephone, 10...Data terminal.

Claims (1)

[Claims] 1. This is a call waiting service method when a data terminal is carrying out data communication in full-duplex mode with a communication partner via a telephone switching network, and the data terminal side from a third party during data communication. When a carrier disconnection from the data terminal is detected on the communication partner side due to an incoming call to, the communication partner side periodically sends a call waiting message to display the message on the data terminal. Call waiting service method.